The present application relates to reaction devices. More specifically, the application relates to a reaction device that can carry out temperature control with high accuracy.
If there is a need to control a reaction based on a temperature condition, it is desired that the temperature condition can be controlled with higher accuracy. Furthermore, it is desired that temperature control can be carried out with high accuracy in a reaction device in which a reaction is performed irrespective of which of liquid, solid, and gas is the reaction target. Such a demand arises also in e.g. the technical field of gene analysis.
One example of the gene analysis technique requiring the high-accuracy temperature control is analysis by use of a polymerase chain reaction (PCR) method, in which gene amplification is performed. The PCR method could be a standard method for quantitative analysis of a trace of nucleic acid.
In the PCR method, the amplification cycle of “thermal denaturation→annealing of primers→polymerase extension reaction” is continuously repeated. This can amplify DNA and so on by a factor of hundreds of thousands. The quantitative analysis of a trace of nucleic acid can also be performed by monitoring the thus obtained PCR-amplified product in real time.
In the PCR method, however, it is necessary that the amplification cycle be controlled accurately. To accurately control the amplification cycle, high-accuracy temperature control is required. Insufficient temperature control leads to a problem that irrelevant DNA sequences are amplified or amplification is not found at all.
Therefore, it is important that the above-described device can carry out thermal control with high accuracy as a reaction device. As techniques relating to this respect, techniques for temperature control of the reaction device are disclosed in Japanese Patent Laid-Open No. 2003-298068 and Japanese Patent Laid-Open No. 2004-025426. In addition, a technique of using semiconductor elements and so on for control of heat generation of a small area is also proposed.